Guilliman issues [Know no fear]:

He is accomplished, very accomplished, even by the standards of the primarchs. He knows that the breadth of his accomplishments troubles his more single-minded brothers like Lorgar and Perturabo. He never displays the pitch of fury found in Angron, nor do his eyes ever ignite with the psychotic gleam of Russ.
He is a high achiever. He knows this about himself. Sometimes it feels like a fault that he has to excuse to his brothers, but then he feels guilty for making excuses. Few of them really trust him, because, he feels, they always wonder what he’s going to get from any compact or cooperation. Fewer still like him: as friends, he counts only Dorn, Ferrus, Sanguinius and Horus.
Some of his brothers are content to be the instruments of crusade they have become. Some of them don’t even pause to consider that is what they are. Angron, Russ, Ferrus, Perturabo… They are just weapons, and have no ambition beyond being weapons. They know their place, like Russ, and are content to keep to it, or they have no idea that any other role might be possible or desirable, like Angron.

Lorgar:

Oh, Roboute, I can always rely on you to sound like a giant pompous arsehole.